The first thing I did was install some 3M Paint Protection Tape on the door sill. The image below shows the tape laying in place (not attached yet) to illustrate how it currently lays on the door sill. This gets covered by the threshold plate, and will protect the paint from getting scratched by the threshold plate (I know, I’m pretty anal). The 3M Paint Protection Tape is very cool. It installs exactly the same way you install an InvisibleShield screen protector on your mobile phone, iPad, or iPod (if you’ve ever done that). It’s basically the same stuff that was developed by the military to protect helicopter blades from whirling dirt and debris.

Here’s a picture of the 3M Paint Protection Paint Installed. I circled the edge of the tape in red to show what the tape looks like. As you can see, it’s clear tape. The white in the previous picture was just the backing.

The next thing I did was build a thin aluminum plate (purchased from the local hardware store) to fit underneath the threshold plate. As you can see from the image below, the original stock door sill rail is gone. The rail is used to hide the edge of the carpet and hold it in place (especially if you don’t have door sill protection plates). The door sill rails were shaved by the previous owner. Not a bad idea, and is something I probably would have done too. They typically get pretty beat up and start to look ugly after a while. Anyway, this threshold plate is designed (imho) to fit over the door sill rails. Since the door sill rails are not present, I felt that the threshold plates needed some support underneath where the rails would have appeared. I drilled 3 holes in the thin aluminum plate to make room for the 3 screws that hold the threshold protection plate to the door sill. I drilled 3 holes in the door sill and used stainless steel screws to attach it. In addition, I used some anti-sieze on the stainless screws to prevent them from galling to the door sill sheet metal.

The aluminum plate I fabricated fits under the threshold protection plate within this channel. I offset the aluminum plate for illustration purposes in this image.